Arma Foil: Critique?

There are several different products.

I have used the "bubble wrap" stuff. It's just your plain old bubble wrap (1/4" bubbles) with Al foil on each side. I have used it around HVAC ducts that pass through un-conditioned space. I have also used the same stuff to help "seal" the joists ends where they go over sill plates in the basement.

I don't know if it's the same company but the bubble wrap stuff (and the Al tape) are sold at HD or Lowes' (don't remembers which).

The other stuff is just for radiation barrier only. One type has holds for water vapor to pass through and the other doesn't.

If you use the stuff which also serves as a vapor barrier you have to use the tape to stop any leaks. Otherwise, the tape just helps to keep overlaps looking neat.